FIELD OF THE INVENTION
The invention relates to a method for separating a medium into a solids-containing component and a liquid component, particularly for the dewatering and drying of waste sludge from nuclear plants, in which the liquid component flows through a filter. The invention relates, furthermore, to an apparatus for carrying out the method.
Various types of solids-containing radioactive waste sludge are produced in nuclear power plants, such as, for example, spheroidal or pulverulent resin sludge or lapping agent suspensions. In order to ensure appropriate intermediate or final storage, waste sludge of this type must first be dewatered and dried before further treatment, for example, before being bound in bitumen or pressed under high pressure. As a result of the dewatering which precedes drying and in which capillary and/or gusset water is separated off and fed to a waste water system, a high material throughput with low energy consumption and therefore effective treatment of the waste can be achieved.
Suction filters are normally used in the dewatering operations of this type. The medium to be dewatered is thereby subjected to excess pressure in a vessel, in the bottom region of which a filter element is arranged. The liquid component of the medium, for example the gusset water, is thereby forced through the filter element. The solids-containing component of the medium is retained by the filter element. The solids-containing filter residue is then normally supplied to a drying stage.
However, the filter elements of such suction filters become clogged rather quickly and they require cleaning or exchange after only short operating periods.